Industrial automation counts on the reliable motion control that linear actuators provide. Lately, electric linear actuators have gotten more popular because they offer better control of variables like speed, acceleration, position and force than pneumatic or hydraulic cylinders. Electric actuators also offer superior accuracy and repeatability, as well as programmable control that can handle even complex motion profiles. In many applications, they can do all this at a lower cost of ownership than pneumatic or hydraulic actuators.

When an engineer is developing a machine design, accuracy is often top-of-mind. So is machine cost. But these two considerations can be at odds since the usual scenario is that the higher the accuracy of a device, the higher the cost. This certainly holds true for electric linear actuators and linear motion systems.

A machine’s useful life depends on the life of its critical components. And machine designers frequently hear the question, “How long can I expect this machine to keep working?”

When electric linear actuators are used, calculating life can be straight-forward for ball screw and roller screw actuators. Since these screw types incorporate rolling elements as essential parts, you can use the L10 life formula for ball bearings.

Let’s say you’ve decided you need a rodless electromechanical actuator to carry a load in your application. Now you have to select a linear drive system. The two most common choices are screw drives and belt drives. Both drive types offer long life, low maintenance, and efficiency in converting the motor’s rotary motion to the carrier’s linear motion. However, each drive type is more suited to particular applications than others, depending on a few key factors.

When you’re called on to specify electric linear actuators, one of the critical decisions you’ll face is whether to use a rodless or rod-style model. Either actuator type has advantages and disadvantages.

In general, if the actuator has to carry a load, a rodless product is what you need. However, if a load needs to be pushed or pulled, select a rod-style actuator.

How FSMA affects linear actuator selection

Until recently, the food processing industry has handled contamination reactively. If a foodborne illness was traced back to contamination at a manufacturing plant, the FDA (Food and Drug Administration) had the manufacturer fix the problem.

The flaw in this system, though, was that most of these illnesses were preventable. The Centers for Disease Control and Prevention estimates that 48 million people (1 in 6 Americans) get sick, 128,000 are hospitalized, and 3,000 die each year from foodborne diseases. That makes food contamination a major public health issue.

The federal government stepped in to change the way the FDA and food producers operate with the Food Safety Modernization Act (FSMA) – signed into law in January 2011. This important legislation shifts the focus to preventing contamination problems instead of just responding to them. FSMA affects all automation components used in the industry, including linear actuators.

Rodless or rod-style linear actuator? It’s a basic and critical decision point for any machine designer. Consider the specifics of your application. Either actuator type has advantages and disadvantages. In general, if a load needs to be pushed or pulled, select an electric rod actuator. However, if you need an actuator to carry a load, a rodless product is what you need. Want to reduce the complexity of a linear motion system? A rodless electromechanical linear actuator can eliminate the need for load-bearing and guiding elements. Also, a rodless actuator can reduce the footprint of a system since its stroke lies completely within its body.

Linear actuators are important pieces of industrial automation equipment. Without them parts wouldn’t move into place for the next production step, finished goods wouldn’t get to the right palate, and tools might not reach the spot they need to be in to do their work.

A lot rides on these automation components, so engineers need to know as much about them as they can. At Tolomatic linear motion is our core expertise. We watch what’s written in key trade publications. Here’s a round-up of recent articles that will help you learn more about linear motion.

Production cost and efficiency are important considerations in all manufacturing, but these factors take on critical status in some segments. Small-engine production is one of these. Using the right linear actuator can boost efficiency and reduce cost.